The present invention relates to a process for combining together unlike yarns in a manner such that the resulting combined yarn does not exhibit regular and reoccurring characteristics but rather is characterized by being non-uniform.
It is well known that yarns formed from staple fibers, particularly from natural fibers such as cotton and wool, are voluminous and bulky. For many years, various and sundry attempts have been made to produce continuous filament synthetic yarns which have bulkiness characteristics comparable to yarns made from such staple fibers. This is, of course, necessary to produce fabrics characterized by a soft, supple hand, fabrics having better moisture-absorbing characteristics and generally the more desirable aesthetic properties attributable to fabrics made from cotton and wool.
Processes for changing continuous filament yarns into yarns which exhibit a greater degree of bulkiness, resilience, resistance to abrasion, warmth and moisture absorption properties and changed surface texture of such yarns can be broken down roughly into six groups. They comprise texturing with air jets, edge crimping by drawing thermoplastic yarns in a heated and stretched condition over a crimping edge, false-twist texturing which simultaneously twists, heat sets and untwists again, gear crimping, knit-de-knit processing and stuffer box crimping. Each of these methods, in its own way, develops stretch and bulk in continuous filament yarns so that the characteristics of fabric woven or knitted therefrom more closely approximates the characteristics traditionally associated with fabrics constructed from natural fiber yarns.
The above processes by and large dealt with a single end of yarn. Accordingly, another method of increasing the bulk of a final yarn is to combine one yarn with another one commonly referred to as doubling. Doubling can include the combining of several strands of sliver, roving or yarn and when carried out by twisting two or more single ends together, the process is also called plying.
There have, however, been many proposals for combining yarns. Attempts have been made to combine untextured or unbulked yarns and thereafter treating the combined yarn in a false-twist or interlacing device where the yarns themselves have differentially shrinkable components to create a bulky yarn. Such a process is discussed in Maerov et al, U.S. Pat. No. 3,199,281. It should be noted that the intent is to produce fabrics which exhibit uniform dyeability characteristics so that such fabric is reproducible.
Another example of combining two yarn ends together is set forth in Gonsalves et al, U.S. Pat. No. 3,302,386. This invention relates to the production of a tangled yarn and specifically the production of a tangled multifilamentary material from one or more untwisted filamentary yarn ends. The yarns Gonsalves et al is employing are untwisted filaments which apparently have not been textured or otherwise pretreated prior to their being combined.
Collingwood et al, U.S. Pat. No. 3,460,336 also forms a composite yarn structure from dark and light colored yarns so as to produce a novelty yarn having contrasting colors therein. While yarns of different colors are being employed they have not been pretextured or crimped. Rather, it is only after the yarns have been combined that they are crimped, twisted or entangled.
Schroeder, U.S. Pat. Nos. 3,496,714 and 3,605,393 describe and claim a bulky yarn and apparatus for forming that bulky yarn which is in the form of a composite yarn produced from two similar and apparently untreated yarns. The yarns are removed from packages and alternately overfed to a fluid jet which tends to form the particular yarn being overfed, at any particular instant, into the effect yarn while the yarn being normally fed would become the core yarn. Overfeeding of the two yarns alternates back and forth between the two yarns, so that each yarn alternately forms the effect portion and thereafter the core portion of the combination yarn. Thus, the bulkiness of the combined yarn relies upon the out of phase relationship of the two yarns as combined as well as the bulkiness given to the otherwise untextured yarn by the jet.
Other processes, such as described in U.S. Pat. No. 3,501,819, have directed the use of air jets to cause complete entanglement of one, two or more multiple filament yarns so that when combined, each of the multifilament yarns looses its individual identity within a single texturized end.
An additional example of an intermingled multifilament yarn is described in Bunting et al, U.S. Pat. No. 3,110,151 which has as its primary objective the production of a coherent compact multifilament yarn having substantially zero twist in the yarn bundle wherein the individual filaments are intermingled with adjacent filaments. The patent describes a process for dealing with filaments of freshly formed or drawn yarn and does not contemplate a process which would employ precrimped or otherwise pretextured yarns as does the present application.
Processes and jet nozzles for uniformly entangling and intermingling textured yarns are also disclosed in London, Jr., et al, U.S. Pat. No. 3,911,655 and Blanc et al, U.S. Pat. No. 3,958,310.